Liquid fuel burner having surface combustion pilot



June 8, 1954 F. B. AUBERT 2,680,479

LIQUID FUEL BURNER HAVING SURFACE COMBUSTION PILOT Filed Sept. 18. 1947 00:00.:l002000Wt:9lI:..'.... e V is i /!9 as 30 "2 F|G.3

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22 26 ATTORNEY Patented June 8, 1954 ICE LIQUID FUEL BURNER HAVING TION PILOT OOMBUS SURFACE Fred B. Aubert, Detroit, Mich.

Application September 18, 1947, Serial No.

5 Claims.

This invention relates to new and useful improvements in liquid fuel burners of the gravity fed type.

One of the objects of this invention is to provide a new and improved liquid fuel burner of the surface combustion type.

Another object is to provide a burner which is particularly adapted for use as a constantly burning pilot.

Another object is to provide a pilot which will operate efiiciently upon a very low consumption of fuel.

Another object is to provide a liquid fuel burner with an improved pilot for an improved normal operation.

Other objects will be apparent from time to time throughout the specification and claims as hereinafter related.

In the accompanying drawings, part of the specification, there fully illustrated two preferred the invention, in which drawings:

Figure 1 is a view in vertical cross-section of to be taken as a for supplying fuel to the pilot,.

Fig. 2 is a plan view of the burner pot and pilot shown in Fig. 1, and

Fig. 3 is a view in vertical cross-section of a burner pot having a fuel well with a pilot therematically showing a fuel valve and conduit for supplying fuel to the well.

Referring to the drawings by characters of refand a perforated upper portion 4 having a plurality of air inlet holes 5. Covering approximately a quadrant of the bottom portion 3 and seating tion pot IS.

the liquid fuel is and ignited the metal strips are heated to ininvention shown in Fig. 3 there is a liquid fuel burner I 5 having a combus- The pot It has a bottom wall portion I! and a perforated side wall portion it which has a plurality of air inlet apertures IS. The pot it has a recessed fuel Well portion 20 which opens upwardly through an aperture 2| in the bottom wall portion ll.

lower portion of the fuel well wall 23 which is operable to receive a fuel supply conduit 2?: which provides gravity flow of fuel from a fuel control valve 21. Positioned in the fuel well portion 20 and extending upwardly through the aperture 2i into the upper portion or zone of combustion of the pot I6 is a rod member 28 of a highly heat conductive metal such as copper. The rod member 28 is operable upon heating to vaporize the fuel supplied to the fuel well portion- 22b. There is an annular disc member 29 carried by a shoulder portion 30 of the rod member 28 which covers and partially closes the aperture 2| leaving only the annular space between the disc member 29 and the pot bottom wall I! for the supply of fuel vapors from the fuel well portion 20 to the pot it. The annular space between the fuel: well wall 23 and the rod member 28 is loosely filled up to the disc member 29 with elongated strips 31- of small cross section of a high melting point oxidation-resistant metal such as fine turnings of one, of the heat-resistant stainless steels heretoforementioned.

In this form of the invention, in Fig. 1, when a small pilot flow of fuel, which may be as small as 1 cc. per minute, is fed to the fuel well portion 26) and ignited the stainless steel turnings are heated to incandescence and thereafter maintain an incandescent surface combustion thereon. When an excess of fuel above that required for pilot combustion is sup? plied a flame 3?. will emerge from the annular space below the disc member 23 and normal com bustion willtalre place in: the burner pot it. During normal combustion in the pot It the rod member 23 is heated and this heat is conducted: to the portion of the rod 28' in the fuel well portion 20 where it is utilized to vaporize. the fuelsupplied thereto. It should be noted that the fuel well air inlet fi l is positioned abovethe maximum level of liquid fuel in the fuel well portion is. The disc member 29 is heated by conductionfrom the rod member 28 and functions to vapors ize liquid fuel particles which may be entrained wtih the fuel vapors emerging space therebelow. When increasing amounts of fuel are supplied to the fuel well portion 20 the fuel is vaporized by the heated rod member 28 and disc member 28 and ignited by the glowing turnings 3| for combustion in pot 15. As was'dee scribed for the form of the invention shown in Fig. 1, when the supply of fuel to the fuel well portion is decreased the size of the flame 32 decreases until it extinguishes itself in the fuel well portion 28, the combustion continuing as surface combustion on the glowing turnings 3|w which function as a continuously burning pilot to subsequently reignite the fuel for another cycle of normal burner operation.

it should be noted that although both forms of the. invention are shown as having the fuel sup plied through the pilot chamber for normal burner operation it would be feasible for the fuel to be supplied by another conduit or other means for normal operation and by the conduit to the pilot chamber for pilot operation without departing from the scope of the invention.

Having thus described the invention, what is claimed and is desired to be secured by Letters Patent of the United States is:

l. A liquid fuel burner comprising a vaporizing pot, a plurality of wall members forming. a Pilot combustion chamber having an outlet into said pot, one of said wall members having an aperture therein for the admission of liquid fuel, one of asin that shown from. the annular all said wall members having an aperture therein for the admission of combustion air at a point above the maximum fuel level in said chamber, loosely dispersed elongated strips of high melting point oxidation-resisting metal of small cross section substantially filling said chamber, and said metal strips being operable to maintain continuous incandescent surface combustion thereon during pilot operation.

2. A liquid fuel burner comprising a vaporizing pot, a wall member forming with the bottom and one of the walls of said pot a pilot combustion chamber having an outlet into said pot, one of the walls of said pot having a fuel inlet aperture and an air inlet aperture into said chamber, the walls of said pot having a plurality of air inlet dispersed elongated strips of high melting point oxidation-resisting metal of small cross section substantially filling said chamber, said metal strips being operable to maintain continuous incandescent surface combustion therein during pilot operation, and said: metal strips while maintaining said continuoussurface combustion being operable to ignite liquid fuel for flame combustion in said pot upon admission of fuel for normal burner operation.

3. A liquid fuel burner comprising a combustion pot, a fuel well portion opening upwardly into the bottom of said pot, means to supply liquid fuel to said fuel well portion, means to supply air for combustion to said pot and to said fuel well portion, loosely dispersed elongated strips of high melting point oxidation-resisting metal of small cross section substantially filling said fuel well portion, said metalstrips being ops erable during pilot operation to maintain a con-i tinuous incandescent. surface combustion thereon, and saidsurface combustion being operable to vaporize and to ignite fuel supplied for combusr. tion in said pot.

4. A liquid fuel burner comprising a combuse tion pot, a fuelwell portion opening upwardly into the bottom of said'pot, means to supply liquid fuel to said fuel' well portion, means to supply air for combustion to said pot and. to said fuel well portion, a fuel vaporization member positioned in said fuel well portion and extending upward into the zone of combustion in said pot, loosely dispersed elongated strips of high melting point oxidation-resisting metal of small cross section substantially filling the space in said fuel well portion surrounding said fuel vaporization member, said metal strips being operable during pilot operation tomaintain a continuous incandescent surface combustion therein, and. said fuel vaporization member being operable to vaporize fuel for combustion during normal operation.

5; A liquid fuel burner comprising a combuse tion pot, a fuel well portion opening upwardly into the bottom of said pot, means to supply liq-s uid' fuel to said fuel well portion, means to suppot and to said fuel well portion, a rod of highly metal positioned in said fuel well portion and extending upward into the zone of combustion in said pot, said rod be'ng operable when heated to vaporize fuel in said fuel well portion, an annular collar member carried by said rod and restricting the opening from said fuel well portion into said pot, loosely dispersed elongated strips of high melting point oxidation-resisting metal of small cross'sect'on substantially filling. the space said fuel well portion surrounding said rod below said collar member, said metal stripsrbe- References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Carrier Mar. 5, 1912 Hemphill Oct. 4, 1921 Elmis Sept. 28, 1926 Breese, Jr. Sept. 6, 1927 Parker et a1. Feb. 23, 1932 Krause Sept. 27, 1932 15 Number 2,185,549 2,194,081 2,287,346 2,307,007 2,308,887 2,332,094 2,388,908 2,396,205

Number Great Britain June 19, 1942 

